scusi revised this gist 10 months ago. Go to revision
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scusi revised this gist 10 months ago. Go to revision
No changes
Florian Walther revised this gist 11 years ago. Go to revision
1 file changed, 1 insertion, 6 deletions
dns_xor.go
| @@ -2,6 +2,7 @@ | |||
| 2 | 2 | // as described on: | |
| 3 | 3 | // https://blog.gdata.de/artikel/neue-variante-von-frameworkpos-schoepft-daten-ueber-dns-anfragen-ab/ | |
| 4 | 4 | // | |
| 5 | + | ||
| 5 | 6 | package main | |
| 6 | 7 | ||
| 7 | 8 | import( | |
| @@ -11,12 +12,6 @@ import( | |||
| 11 | 12 | "flag" | |
| 12 | 13 | ) | |
| 13 | 14 | ||
| 14 | - | // test vectors: | |
| 15 | - | // data := []byte{0xc3, 0xcb, 0xc0, 0xdc, 0xc3, 0xc4, 0xca, 0xdc, 0xc4, 0xcb, 0xdc, 0xc4, 0xcb} | |
| 16 | - | // string := "192.168.69.69" | |
| 17 | - | // | |
| 18 | - | // data := []byte{0xa2, 0xb3, 0xa7, 0xbe, 0xdf, 0xb3, 0xb0, 0xb1, 0xc3, 0xc0, 0xc1, 0xc6} | |
| 19 | - | // string := "PAUL-ABC1234" | |
| 20 | 15 | const A = 0xAA | |
| 21 | 16 | const B = 0x9B | |
| 22 | 17 | const C = 0xC3 | |
Florian Walther revised this gist 11 years ago. Go to revision
1 file changed, 71 insertions
dns_xor.go(file created)
| @@ -0,0 +1,71 @@ | |||
| 1 | + | // domain data encoding/decoding algo for FrameworkPOS Malware DNS-Tunneling Variant, | |
| 2 | + | // as described on: | |
| 3 | + | // https://blog.gdata.de/artikel/neue-variante-von-frameworkpos-schoepft-daten-ueber-dns-anfragen-ab/ | |
| 4 | + | // | |
| 5 | + | package main | |
| 6 | + | ||
| 7 | + | import( | |
| 8 | + | "fmt" | |
| 9 | + | "os" | |
| 10 | + | "encoding/hex" | |
| 11 | + | "flag" | |
| 12 | + | ) | |
| 13 | + | ||
| 14 | + | // test vectors: | |
| 15 | + | // data := []byte{0xc3, 0xcb, 0xc0, 0xdc, 0xc3, 0xc4, 0xca, 0xdc, 0xc4, 0xcb, 0xdc, 0xc4, 0xcb} | |
| 16 | + | // string := "192.168.69.69" | |
| 17 | + | // | |
| 18 | + | // data := []byte{0xa2, 0xb3, 0xa7, 0xbe, 0xdf, 0xb3, 0xb0, 0xb1, 0xc3, 0xc0, 0xc1, 0xc6} | |
| 19 | + | // string := "PAUL-ABC1234" | |
| 20 | + | const A = 0xAA | |
| 21 | + | const B = 0x9B | |
| 22 | + | const C = 0xC3 | |
| 23 | + | ||
| 24 | + | var op string | |
| 25 | + | var in string | |
| 26 | + | ||
| 27 | + | func init(){ | |
| 28 | + | flag.StringVar(&op, "op", "decode", "operation to perform: 'encode' or 'decode', default is 'decode'") | |
| 29 | + | flag.StringVar(&in, "in", "", "Inputstring to perform choosen operation on") | |
| 30 | + | } | |
| 31 | + | ||
| 32 | + | // decode - decodes single values from dns queries into cleartext | |
| 33 | + | func decode(data []byte)(result []byte){ | |
| 34 | + | for _, v := range data { | |
| 35 | + | a := v ^ A | |
| 36 | + | b := a ^ B | |
| 37 | + | result = append(result, b ^ C) | |
| 38 | + | } | |
| 39 | + | return result | |
| 40 | + | } | |
| 41 | + | ||
| 42 | + | // encode - encodes cleartext values to be used in dns queries | |
| 43 | + | func encode(data []byte)(result []byte) { | |
| 44 | + | for _, v := range data { | |
| 45 | + | b := v ^ C | |
| 46 | + | a := b ^ B | |
| 47 | + | result = append(result, a ^ A) | |
| 48 | + | } | |
| 49 | + | return result | |
| 50 | + | } | |
| 51 | + | ||
| 52 | + | func main(){ | |
| 53 | + | flag.Parse() | |
| 54 | + | input := []byte(in) | |
| 55 | + | ||
| 56 | + | switch { | |
| 57 | + | case op == "encode": | |
| 58 | + | encoded := encode(input) | |
| 59 | + | fmt.Printf("%s %x\n", input, string(encoded)) | |
| 60 | + | case op == "decode": | |
| 61 | + | data, err := hex.DecodeString(string(input)) | |
| 62 | + | if err != nil { | |
| 63 | + | panic(err) | |
| 64 | + | } | |
| 65 | + | decoded := decode(data) | |
| 66 | + | fmt.Printf("%x %s\n", data, string(decoded)) | |
| 67 | + | default: | |
| 68 | + | prog := os.Args[0] | |
| 69 | + | fmt.Printf("For USAGE INFO call: '%s -h'\n", prog) | |
| 70 | + | } | |
| 71 | + | } | |
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